🇦🇷 Argentina · Hypothetical site
Sierra de las Quijadas — Potrero de la Aguada Enigmatic Walls
Holocene natural / possibly Late Holocene human (unvalidated) · Unassigned Huarpes / Comechingón? / Jesuit?
Erosive 4000 ha Potrero de la Aguada amphitheatre inside Quijadas range — 40–80 m low stone walls bracketing stream forks, culture debated.